Conventionally, power storage devices are used as a power source in various kinds of electronic equipment. For example, Japanese Patent Application Laid-Open No. 2015-146252 (Patent Document 1) discloses a power storage device having an electrode laminate in which a positive electrode, a separator and a negative electrode are laminated together. In this power storage device, the positive electrode is smaller than the negative electrode and the separator is larger than the negative electrode so as to prevent a short circuit between the positive and negative electrodes.
In recent years, electronic equipment has been increasingly miniaturized and thus the need for thinner and smaller power storage devices has increased. A main object of the present invention is to provide a power storage device which is thin and small.